This invention relates generally to a system and method for connecting materials that are typically difficult to connect together, and particularly to assembling sections of a bicycle frame that can be disassembled for convenient transport and storage.
In typical applications where it is desirable to connect two different materials together, it is often not attempted due to the problems ensuring a good connection. In one example, a bicycle frame may have one or more different pieces that are made of different materials, such as metal parts that need to be connected to carbon fiber parts. Typically, it is necessary to bond the carbon fiber parts to the metal part although the bonding process is not very strong and tends to break. The bonding process is also susceptible to corrosion and requires the builder to have specialized skills and equipment. Thus, the typical bonding process has undesirable drawbacks including a weak connection between the two different parts that is susceptible to breakage. Thus, it is desirable to provide a system for connecting parts of two different materials, such as different parts of a bicycle frame, and it is to this end that the present invention is directed.
FIG. 14 shows a conventional bicycle 1 which generally includes a front wheel 2, pedals 4, a rear derailleur 6 for moving a chain 5 over a sprocket cassette 7 attached to a rear wheel 3, and hand brakes 9 attached to handlebars 10. These components are in fixed positions relative to one another and to a triangular bicycle frame that includes a top tube 12, a down tube 13, and a seat tube 16. The seat tube 16, the down tube 13, and the pedal assembly 4 meet at a bottom bracket shell that is not shown in the figure. The “pedal assembly,” as used herein, includes a crank, pedals, and various peripheral components that make the pedals function properly. Also extending from the bottom bracket is a pair of chain stays 15a. The chain stays 15a, of which only one is shown, connect the pedal assembly to the hub of the rear wheel 3 on both sides of the rear wheel 3. A pair of seat stays 150 connect the hub of the rear wheel 3 to the top of the seat tube 16 on both sides of the rear wheel 3. The chain stays 15 and the seat stays 150 connect at the hub of the rear wheel 3 so as to form a V-shape on either side of the bicycle 1. The angled portion of the V-shaped chain stay 15 is attached to an area near the hub of the rear wheel 3 and the two ends connect to the hidden bottom bracket and the seat tube 16, respectively. The seat tube 16 supports the bicycle seat 18 by holding up the seat post 17.
A rider uses the handlebars 9 to steer the bicycle in the desired direction. Located near the handlebars 9 are hand brakes 8 and gear shifter 10. The hand brakes 8 are coupled to the brakes by a rear wheel brake cable 112a and a front wheel brake cable 112b. Similarly, the gear shifter 10 shifts gears by activating the rear derailleur 6 and a derailleur 19 to which it is connected by two respective derailleur cables. Only part of the derailleur cables are shown as derailleur cable 113 in order to avoid cluttering the figure.
The triangular bicycle frame is typically a one-piece member so that it occupies a large space and is inconvenient to be carried and stored. The one-piece frame also increases the space required to store the frame and incurs airline cargo charges. A bicycle frame that is easy to store and transport while being at least as sturdy and reliable as the one-piece bicycle is necessary.